4. A copper rod of length 1 m expands in length by 1.7 mm for a rise in temperature of 100 °C. What will be the approximate area of a copper sheet of size 1 m x 1m when its temperature is increased by 100 °C [Ans.: 1.0034 m]
But how is this solved??
But how is this solved??
Answers & Comments
Answer:
ΔT=100−0=100°C
ΔL/L=length=L=1%=1/100=0.01
ΔL=αLΔT
ΔL/L=α×100
0.01=α×100
α=0.01/100=1×10
−4
Given Area of copper plate =2L×L=2L
2
By thermal expansion theory,
ΔA=βAΔT
ΔA/A=βΔT
but,
β=2α
ΔA/A=2αΔT
=2×1×10
−
4×100
=2×10
−
2
ΔA/A×100=2×10
−2
×100=2%